This study is a multicenter,open-label,randomized, phase II clinical study conducted in China. The purpose of this study is to evaluate the efficacy of SKB315 plus PD-1 inhibitor ±capecitabine in patients with Unresectable Locally Advanced or Metastatic Gastric or Gastroesophageal Junction Adenocarcinoma
Locally advanced unresectable or metastatic gastric cancer (GC) or gastroesophageal junction (GEJ) carcinoma and have histologically confirmed adenocarcinoma
No previous systemic therapy for locally advanced unresectable or metastatic gastric/GEJ cancer.
Consent to provide archival or fresh tumor tissue slides for immunohistochemistry (IHC) assessment, and advanced solid tumors with Claudin 18.2 and PD-L1 expression as determined by IHC;
Presence of at least one measurable lesion based on Response Evaluation Criteria in Solid Tumors (RECIST) v1.1;
Active leptomeningeal disease or uncontrolled brain metastasis
Diagnosed with gastric or GEJ adenocarcinoma with positive HER2
Received other drugs in clinical study, major surgeries, or any other antitumor therapies within 4 weeks prior to the first dose of study treatment;
Patients with active hepatitis B or hepatitis C;